Genetic Phenomena Commons^™

Absence Of Btk, Bcl2, And Plcg2 Mutations In Chronic Lymphocytic Leukemia Relapsing After First-Line Treatment With Fixed-Duration Ibrutinib Plus Venetoclax, Nitin Jain, Lisa J Croner, John N Allan, Tanya Siddiqi, Alessandra Tedeschi, Xavier C Badoux, Karl Eckert, Leo W K Cheung, Anwesha Mukherjee, James P Dean, Edith Szafer-Glusman, John F Seymour

Faculty, Staff and Student Publications

Purpose: Mutations in BTK, PLCG2, and BCL2 have been reported in patients with progressive disease (PD) on continuous single-agent BTK or BCL2 inhibitor treatment. We tested for these mutations in samples from patients with PD after completion of first-line treatment with fixed-duration ibrutinib plus venetoclax for chronic lymphocytic leukemia (CLL) in the phase II CAPTIVATE study.

Patients and methods: A total of 191 patients completed fixed-duration ibrutinib plus venetoclax (three cycles of ibrutinib then 12-13 cycles of ibrutinib plus venetoclax). Genomic risk features [del(11q), del(13q), del(17p), trisomy 12, complex karyotype, unmutated IGHV, TP53 mutated] and mutations in genes recurrently mutated …

Trex2 Deficiency Suppresses Spontaneous And Genotoxin-Associated Mutagenesis, Teresa Marple, Mi Young Son, Xiaodong Cheng, Jun Ho Ko, Patrick Sung, Paul Hasty

Faculty, Staff and Student Publications

TREX2, a 3'-5' exonuclease, is a part of the DNA damage tolerance (DDT) pathway that stabilizes replication forks (RFs) by ubiquitinating PCNA along with the ubiquitin E3 ligase RAD18 and other DDT factors. Mismatch repair (MMR) corrects DNA polymerase errors, including base mismatches and slippage. Here we demonstrate that TREX2 deletion reduces mutations in cells upon exposure to genotoxins, including those that cause base lesions and DNA polymerase slippage. Importantly, we show that TREX2 generates most of the spontaneous mutations in MMR-mutant cells derived from mice and people. TREX2-induced mutagenesis is dependent on the nuclease and DNA-binding attributes of TREX2. …

An Incidental Finding Of A High-Grade Glioma With Pleomorphic And Pseudopapillary Features (Hpap) With Pbrm1 Mutation, Maria A Gubbiotti, Jeffrey S Weinberg, Shiao-Pei Weathers, Pushan Dasgupta, Martin C Tom, Kenneth Aldape, Martha Quezado, Zied Abdullaev, Jason T Huse, Leomar Y Ballester

Faculty, Staff and Student Publications

No abstract provided.

Effects Of Kras Genetic Interactions On Outcomes In Cancers Of The Lung, Pancreas, And Colorectum, Isabella N Grabski, John V Heymach, Kenneth L Kehl, Scott Kopetz, Ken S Lau, Gregory J Riely, Deborah Schrag, Rona Yaeger, Rafael A Irizarry, Kevin M Haigis

Faculty, Staff and Student Publications

Background: KRAS is among the most commonly mutated oncogenes in cancer, and previous studies have shown associations with survival in many cancer contexts. Evidence from both clinical observations and mouse experiments further suggests that these associations are allele- and tissue-specific. These findings motivate using clinical data to understand gene interactions and clinical covariates within different alleles and tissues.

Methods: We analyze genomic and clinical data from the AACR Project GENIE Biopharma Collaborative for samples from lung, colorectal, and pancreatic cancers. For each of these cancer types, we report epidemiological associations for different KRAS alleles, apply principal component analysis (PCA) to …

Dysregulation Of Epigenetic Modifications In Inborn Errors Of Immunity, Zhongyao Xiao, Rongjing He, Zihan Zhao, Taiping Chen, Zhengzhou Ying

Faculty, Staff and Student Publications

Inborn errors of immunity (IEIs) are a group of typically monogenic disorders characterized by dysfunction in the immune system. Individuals with these disorders experience increased susceptibility to infections, autoimmunity and malignancies due to abnormal immune responses. Epigenetic modifications, including DNA methylation, histone modifications and chromatin remodeling, have been well explored in the regulation of immune cell development and effector function. Aberrant epigenetic modifications can disrupt gene expression profiles crucial for immune responses, resulting in impaired immune cell differentiation and function. Dysregulation of these processes caused by mutations in genes involving in epigenetic modifications has been associated with various IEIs. In …

Fgf5, Evelyn A Carrion, Malcolm M Moses, Richard R Behringer

Faculty, Staff and Student Publications

FGF5 functions as a negative regulator of the hair cycle in mammals. It is expressed in the outer root sheath of hair follicles during the late anagen phase of the hair cycle. It functions as a signaling molecule, mediating the transition of the anagen growth phase to catagen regression phase of the hair cycle. Spontaneous and engineered FGF5 mutations in mammalian animal models result in long hair phenotypes. In humans, inherited FGF5 mutations result in trichomegaly (long eyelashes). Knockdown of fgf5 in zebrafish embryos results in inner ear alterations. Alterations in FGF5 expression are also associated with various human pathologies.

Circulating Tumor Dna (Ctdna) As A Biomarker Of Response To Therapy In Advanced Hepatocellular Carcinoma Treated With Nivolumab, Yehia I Mohamed, Sunyoung S Lee, Tarik Demir, Shadi Chamseddine, Zishuo Ian Hu, Lianchun Xiao, Khaled Elsayes, Jeffrey S Morris, Robert A Wolff, Rikita Hiatia, Aliya Qayyum, Asif Rashid, Dan G Duda, James C Yao, Michael Lapelusa, Eugene J Koay, Armeen Mahvash, Ahmed Al Azzam, Ecaterina E Dumbrava, Manal Hassan, Hesham M Amin, Ahmed Omar Kaseb

Faculty, Staff and Student Publications

Background: Circulating tumor DNA (ctDNA) is a promising non-invasive marker for detection, diagnosis, treatment selection, and prognosis of hepatocellular carcinoma (HCC).

Objective: This study aimed to examine the utility of ctDNA as a prognostic and predictive tool in HCC patients treated with nivolumab.

Methods: We analyzed pre-treatment ctDNA from 44 HCC patients using comprehensive genomic testing on a commercially available platform. We utilized log rank test and univariate Cox models to correlate overall survival (OS) and progression-free survival (PFS) with ctDNA expressions.

Results: Of 44 patients, 77.3% were men with median age of 67 years. All but 3 patients had …

P53r245w Mutation Fuels Cancer Initiation And Metastases In Nash-Driven Liver Tumorigenesis, Denada Dibra, Mihai Gagea, Yuan Qi, Gilda P Chau, Xiaoping Su, Guillermina Lozano

Faculty, Staff and Student Publications

Obesity is a significant global health concern. Non-alcoholic fatty liver disease and non-alcoholic steatohepatitis (NASH) are common risk factors for hepatocellular carcinoma (HCC) and are closely associated with metabolic comorbidities, including obesity and diabetes. The TP53 tumor suppressor is the most frequently mutated gene in liver cancers, with half of these alterations being missense mutations. These mutations produce highly abundant proteins in cancer cells which have both inhibitory effects on wildtype (WT) p53, and gain-of-function (GOF) activities that contribute to tumor progression. A Western diet increases p53 activity in the liver. To elucidate the functional consequences of Trp53 mutations in …

Precision Therapy For A Medically Actionable Atp1a3 Variant From A Genomic Medicine Program In An Underserved Population, Cara P Ford, Rebecca O Littlejohn, Ryan German, Blake Vuocolo, Jose Aceves, Liesbeth Vossaert, Nichole Owen, Michael Wangler, Carrie A Schmid

Duncan NRI Faculty and Staff Publications

Background: Genomic medicine is revolutionizing the diagnosis of rare diseases, but the implementation has not benefited underrepresented populations to the same degree. Here, we report the case of a 7-year-old boy with hypotonia, global developmental delay, strabismus, seizures, and previously suspected mitochondrial myopathy. This proband comes from an underrepresented minority and was denied exome sequencing by his public insurance.

Methods: After informed consent was obtained, buccal cells from the proband were collected and whole exome sequencing was performed. Illumina Dragen and Emedgene software was used to analyze the data at Baylor Genetics. The variants were further intepreted according to ACMG …

Acute Myeloid Leukemia With Mutated Tp53: Is This Newly Proposed Entity Oversimplifying A Complex Group Of Neoplasms?, Hong Fang, L Jeffery Medeiros, Wei Wang

Faculty, Staff and Student Publications

No abstract provided.

Enhanced Cd19 Activity In B Cells Contributes To Immunodeficiency In Mice Deficient In The Icf Syndrome Gene Zbtb24, Zhengzhou Ying, Swanand Hardikar, Joshua B Plummer, Tewfik Hamidi, Bin Liu, Yueping Chen, Jianjun Shen, Yunxiang Mu, Kevin M Mcbride, Taiping Chen

Faculty, Staff and Student Publications

Immunodeficiency, centromeric instability, and facial anomalies (ICF) syndrome is a rare autosomal recessive disorder characterized by DNA hypomethylation and antibody deficiency. It is caused by mutations in DNMT3B, ZBTB24, CDCA7, or HELLS. While progress has been made in elucidating the roles of these genes in regulating DNA methylation, little is known about the pathogenesis of the life-threatening hypogammaglobulinemia phenotype. Here, we show that mice deficient in Zbtb24 in the hematopoietic lineage recapitulate the major clinical features of patients with ICF syndrome. Specifically, Vav-Cre-mediated ablation of Zbtb24 does not affect lymphocyte development but results in reduced plasma cells and low levels …

Kinome Profiling Identifies Mark3 And Stk10 As Potential Therapeutic Targets In Uveal Melanoma, Usman Baqai, Alison M Kurimchak, Isabella V Trachtenberg, Timothy J Purwin, Jelan I Haj, Anna Han, Kristine Luo, Nikole Fandino Pachon, Angela Jeon, Vivian Chua, Michael A Davies, J Silvio Gutkind, Jeffrey L Benovic, James S Duncan, Andrew E Aplin

Faculty, Staff and Student Publications

Most uveal melanoma cases harbor activating mutations in either GNAQ or GNA11. Despite activation of the mitogen-activated protein kinase (MAPK) signaling pathway downstream of Gαq/11, there are no effective targeted kinase therapies for metastatic uveal melanoma. The human genome encodes numerous understudied kinases, also called the "dark kinome". Identifying additional kinases regulated by Gαq/11 may uncover novel therapeutic targets for uveal melanoma. In this study, we treated GNAQ-mutant uveal melanoma cell lines with a Gαq/11 inhibitor, YM-254890, and conducted a kinase signaling proteomic screen using multiplexed-kinase inhibitors followed by mass spectrometry. We observed downregulated expression and/or activity of 22 kinases. …

The Landscape Of Alterations From 1407 Ultra-Rare Sarcomas From The Aacr Genie Database: Clinical Implications, Ryan A Denu, Justin T Moyers, Mohamed A Gouda, Anthony P Conley, Alexander J Lazar, Vivek Subbiah

Faculty, Staff and Student Publications

Purpose: Ultra-rare sarcomas (URS) comprise a group of orphan diseases with an incidence of ≤1/1,000,000 people per year. We aimed to assess clinically actionable genomic alterations in URS.

Experimental design: Data were extracted from the GENIE database using cBioPortal. OncoKB was used to assess for clinical actionability of mutations. Tumor mutational burden (TMB) was inferred from clinical sequencing data.

Results: Soft tissue (ST) URS made up 23.5% of ST sarcoma cases, and bone URS made up 16.5% of bone sarcoma cases. The most commonly mutated gene in all four groups was TP53. The most common fusions involved EWSR1. The most …

Cigarette Smoke Exposure Accelerates Aml Progression In Flt3-Itd Models, Mary Figueroa, Huaxian Ma, Mansour Alfayez, Daniel Enrique Morales-Mantilla, Fei Wang, Yue Lu, Marcos R Estecio, Katherine Y King, Eugenie Kleinerman, Seyed Javad Moghaddam, Naval Daver, Michael Andreeff, Marina Konopleva, Courtney Dinardo, Joya Chandra

Faculty, Staff and Student Publications

No abstract provided.

Single-Cell Analysis Differentiates The Effects Of P53 Mutation And P53 Loss On Cell Compositions Of Oncogenic Kras-Driven Pancreatic Cancer, Xinlei Sun, Daowei Yang, Yang Chen

Faculty, Staff and Student Publications

Pancreatic ductal adenocarcinoma (PDAC) is a devastating malignant disease with a dismal prognosis. In the past decades, a plethora of genetically engineered mouse models (GEMMs) with autochthonous pancreatic tumor development have greatly facilitated studies of pancreatic cancer. Commonly used GEMMs of PDAC often harbor the oncogenic KRAS driver mutation (KrasG12D), in combination with either p53 mutation by knock-in strategy (Trp53R172H) or p53 loss by conditional knockout (Trp53cKO) strategy, in pancreatic cell lineages. However, the systematic comparison of the tumor microenvironment between KrasG12D; Trp53R172H (KPmut) mouse models and KrasG12D; Trp53cKO (KPloss) mouse models …

Venetoclax Abrogates The Prognostic Impact Of Splicing Factor Gene Mutations In Newly Diagnosed Acute Myeloid Leukemia, Jayastu Senapati, Samuel Urrutia, Sanam Loghavi, Nicholas J Short, Ghayas C Issa, Abhishek Maiti, Hussein A Abbas, Naval G Daver, Naveen Pemmaraju, Sherry Pierce, Kelly S Chien, Koji Sasaki, Tapan M Kadia, Danielle E Hammond, Gautam Borthakur, Keyur Patel, Farhad Ravandi, Hagop M Kantarjian, Guillermo Garcia-Manero, Courtney D Dinardo

Faculty, Staff and Student Publications

Mutations in splicing factor (SF) genes SRSF2, U2AF1, SF3B1, and ZRSR2 are now considered adverse risk in the European LeukemiaNet 2022 acute myeloid leukemia (AML) risk stratification. The prognostic impact of SF mutations in AML has been predominantly derived from younger patients treated with intensive (INT) therapy. We evaluated 994 patients with newly diagnosed AML, including 266 (27%) with a SFmut. Median age was 67 years overall, with patients with SFmut being older at 72 years. SRSF2 (n = 140, 53%) was the most common SFmut. In patients treated with INT, median relapse-free survival (RFS) (9.6 vs 21.4 months, P …

Egfr Tyrosine Kinase Inhibitors For The Treatment Of Metastatic Non-Small Cell Lung Cancer Harboring Uncommon Egfr Mutations: A Podcast, Xiuning Le, Eric Nadler, Daniel B Costa, John Victor Heymach

Faculty, Staff and Student Publications

See the video and supplementary file.

Characteristics And Clinical Outcomes Of Patients With Myeloid Malignancies And Ddx41 Variants, Alex Bataller, Sanam Loghavi, Yoheved Gerstein, Alexandre Bazinet, Koji Sasaki, Kelly S Chien, Danielle Hammond, Guillermo Montalban-Bravo, Gautam Borthakur, Nicholas Short, Ghayas C Issa, Tapan M Kadia, Naval Daver, Guilin Tang, Andres Quesada, Keyur P Patel, Farhad Ravandi, Warren Fiskus, Cristopher P Mill, Hagop M Kantarjian, Kapil Bhalla, Guillermo Garcia-Manero, Betul Oran, Courtney D Dinardo

Faculty, Staff and Student Publications

DDX41 is the most frequently mutated gene in myeloid neoplasms associated with germline predisposition including myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). We analyzed 3795 patients with myeloid neoplasms and identified 151 (4%) with DDX41 variants and a diagnosis of AML (n = 96), MDS (n = 52), and chronic myelomonocytic leukemia (n = 3). The most frequent DDX41 variants were the somatic variant p.R525H, followed by the germline variants p.M1I and p.D140fs. Most neoplasms had a normal karyotype (59%) and the most frequent co-mutations were TP53 (16%) and ASXL1 (15%). 30% of patients had no concomitant mutations besides …

Guide-Specific Loss Of Efficiency And Off-Target Reduction With Cas9 Variants, Liang Zhang, Wei He, Rongjie Fu, Shuyue Wang, Yiwen Chen, Han Xu

Faculty, Staff and Student Publications

High-fidelity clustered regularly interspaced palindromic repeats (CRISPR)-associated protein 9 (Cas9) variants have been developed to reduce the off-target effects of CRISPR systems at a cost of efficiency loss. To systematically evaluate the efficiency and off-target tolerance of Cas9 variants in complex with different single guide RNAs (sgRNAs), we applied high-throughput viability screens and a synthetic paired sgRNA-target system to assess thousands of sgRNAs in combination with two high-fidelity Cas9 variants HiFi and LZ3. Comparing these variants against wild-type SpCas9, we found that ∼20% of sgRNAs are associated with a significant loss of efficiency when complexed with either HiFi or LZ3. …

Pls3 Missense Variants Affecting The Actin-Binding Domains Cause X-Linked Congenital Diaphragmatic Hernia And Body-Wall Defects, Florence Petit, Mauro Longoni, Julie Wells, Richard S Maser, Eric L Bogenschutz, Matthew J Dysart, Hannah T M Contreras, Frederic Frénois, Barbara R Pober, Robin D Clark, Philip F Giampietro, Hilger H Ropers, Hao Hu, Maria Loscertales, Richard Wagner, Xingbin Ai, Harrison Brand, Anne-Sophie Jourdain, Marie-Ange Delrue, Brigitte Gilbert-Dussardier, Louise Devisme, Boris Keren, David J Mcculley, Lu Qiao, Rebecca Hernan, Julia Wynn, Tiana M Scott, Daniel G Calame, Zeynep Coban-Akdemir, Patricia Hernandez, Andres Hernandez-Garcia, Hagith Yonath, James R Lupski, Yufeng Shen, Wendy K Chung, Daryl A Scott, Carol J Bult, Patricia K Donahoe, Frances A High

Faculty, Staff and Student Publications

Congenital diaphragmatic hernia (CDH) is a relatively common and genetically heterogeneous structural birth defect associated with high mortality and morbidity. We describe eight unrelated families with an X-linked condition characterized by diaphragm defects, variable anterior body-wall anomalies, and/or facial dysmorphism. Using linkage analysis and exome or genome sequencing, we found that missense variants in plastin 3 (PLS3), a gene encoding an actin bundling protein, co-segregate with disease in all families. Loss-of-function variants in PLS3 have been previously associated with X-linked osteoporosis (MIM: 300910), so we used in silico protein modeling and a mouse model to address these seemingly disparate clinical …

Kras G12c In Advanced Nsclc: Prevalence, Co-Mutations, And Testing, Tony Kiat Hon Lim, Ferdinandos Skoulidis, Keith M Kerr, Myung-Ju Ahn, Joshua R Kapp, Fernando A Soares, Yasushi Yatabe

Faculty, Staff and Student Publications

KRAS is the most commonly mutated oncogene in advanced, non-squamous, non-small cell lung cancer (NSCLC) in Western countries. Of the various KRAS mutants, KRAS G12C is the most common variant (~40%), representing 10-13% of advanced non-squamous NSCLC. Recent regulatory approvals of the KRASG12C-selective inhibitors sotorasib and adagrasib for patients with advanced or metastatic NSCLC harboring KRASG12C have transformed KRAS into a druggable target. In this review, we explore the evolving role of KRAS from a prognostic to a predictive biomarker in advanced NSCLC, discussing KRAS G12C biology, real-world prevalence, clinical relevance of co-mutations, and approaches to molecular testing. Real-world evidence …

Characteristics And Outcomes Of Patients With Chronic Myeloid Leukemia And T315i Mutation Treated In The Pre- And Post-Ponatinib Era, Fadi G Haddad, Koji Sasaki, Aram Bidikian, Ghayas C Issa, Tapan Kadia, Nitin Jain, Yesid Alvarado, Nicholas J Short, Naveen Pemmaraju, Sanam Loghavi, Keyur P Patel, Rashmi Kanagal-Shamanna, Musa Yilmaz, Lucia Masarova, Elias Jabbour, Hagop Kantarjian

Faculty, Staff and Student Publications

Patients with chronic myeloid leukemia (CML) and T315I mutation generally have a poor prognosis. Their outcome in the post-ponatinib era remains unclear. We reviewed patients with CML in chronic (CP) or accelerated phase (AP) who developed a T315I mutation between March 15, 2004, and July 26, 2022. Patients were divided into CP, AP, or blastic phase (BP) at the time of mutation detection. Overall survival (OS) was defined from the time of mutation detection to the date of death or last follow-up. We identified a total of 107 patients: 54 (51%) in CP, 14 (13%) in AP, and 39 (36%) …

Treatment Of Older Adults With Flt3-Mutated Aml: Emerging Paradigms And The Role Of Frontline Flt3 Inhibitors, Nicholas J Short, Daniel Nguyen, Farhad Ravandi

Faculty, Staff and Student Publications

FLT3 is the most frequently mutated gene in acute myeloid leukemia (AML), with FLT3 internal tandem duplication (ITD) mutations being associated with a more aggressive clinical course. While two large, randomized clinical trials have shown a survival benefit with the frontline use of an oral FLT3 inhibitor (midostaurin or quizartinib) in patients with FLT3-mutated AML, the role of FLT3 inhibitors in older adults with newly diagnosed FLT3-mutated AML remains unclear. A definitive improvement in survival has not been observed in intensively treated patients over 60 years of age receiving frontline FLT3 inhibitors. Furthermore, many patients with FLT3-mutated AML are unsuitable …

Inhibition Of Menin, Bcl-2, And Flt3 Combined With A Hypomethylating Agent Cures Npm1/Flt3-Itd/-Tkd Mutant Acute Myeloid Leukemia In A Patient-Derived Xenograft Model, Bing Z Carter, Po Yee Mak, Wenjing Tao, Lauren B Ostermann, Duncan H Mak, Baozhen Ke, Peter Ordentlich, Gerard M Mcgeehan, Michael Andreeff

Faculty, Staff and Student Publications

No abstract provided.

Cobimetinib Plus Vemurafenib In Patients With Solid Tumors With Braf Mutations: Results From The Targeted Agent And Profiling Utilization Registry Study, Funda Meric-Bernstam, Michael Rothe, Pam K Mangat, Elizabeth Garrett-Mayer, Rodolfo Gutierrez, Eugene R Ahn, Timothy L Cannon, Steven Powell, John C Krauss, Christopher M Reynolds, Margaret Von Mehren, Deepti Behl, Carmen J Calfa, Herbert L Duvivier, Henry G Kaplan, Michael B Livingston, Manish R Sharma, Walter J Urba, Gina N Grantham, Dominique C Hinshaw, Abigail Gregory, Susan Halabi, Richard L Schilsky

Faculty, Staff and Student Publications

Purpose: The Targeted Agent and Profiling Utilization Registry Study is a phase II basket study evaluating antitumor activity of commercially available targeted agents in patients with advanced cancers with genomic alterations known to be drug targets. The results in a cohort of patients with solid tumors with BRAF mutations treated with cobimetinib plus vemurafenib are reported.

Methods: Eligible patients had measurable disease (RECIST v.1.1), Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, and no standard treatment options. The primary end point was disease control (DC), defined as complete response (CR) or partial response (PR) or stable disease of …

Adagrasib In Advanced Solid Tumors Harboring A Krasg12c Mutation, Tanios S Bekaii-Saab, Rona Yaeger, Alexander I Spira, Meredith S Pelster, Joshua K Sabari, Navid Hafez, Minal Barve, Karen Velastegui, Xiaohong Yan, Aditya Shetty, Hirak Der-Torossian, Shubham Pant

Faculty, Staff and Student Publications

Purpose: Adagrasib, a KRASG12C inhibitor, has demonstrated clinical activity in patients with KRASG12C-mutated non-small-cell lung cancer (NSCLC) and colorectal cancer (CRC). KRASG12C mutations occur rarely in other solid tumor types. We report evaluation of the clinical activity and safety of adagrasib in patients with other solid tumors harboring a KRASG12C mutation.

Methods: In this phase II cohort of the KRYSTAL-1 study (ClinicalTrials.gov identifier: NCT03785249; phase Ib cohort), we evaluated adagrasib (600 mg orally twice daily) in patients with KRASG12C-mutated advanced solid tumors (excluding NSCLC and CRC). The primary end point was objective response …

Triple-Negative Breast Tumors Are Dependent On Mutant P53 For Growth And Survival, Denada Dibra, Sydney M Moyer, Adel K El-Naggar, Yuan Qi, Xiaoping Su, Guillermina Lozano

Faculty, Staff and Student Publications

The TP53 tumor suppressor gene is mutated early in the majority of patients with triple-negative breast cancer (TNBC). The most frequent TP53 alterations are missense mutations that contribute to tumor aggressiveness. We developed an autochthonous somatic K14-Cre driven TNBC mouse model with p53R172H and p53R245W mutations in which mutant p53 can be toggled on and off genetically while leaving the tumor microenvironment intact and wild-type for p53. These mice develop TNBCs with a median latency of 1 y. Deletion of mutant p53R172H or p53R245W in vivo in these tumors blunts their tumor growth and significantly extends survival of mice. Downstream …

Loss Of Syncrip Unleashes Apobec-Driven Mutagenesis, Tumor Heterogeneity, And Ar-Targeted Therapy Resistance In Prostate Cancer, Xiaoling Li, Yunguan Wang, Su Deng, Guanghui Zhu, Choushi Wang, Nickolas A Johnson, Zeda Zhang, Carla Rodriguez Tirado, Yaru Xu, Lauren A Metang, Julisa Gonzalez, Atreyi Mukherji, Jianfeng Ye, Yuqiu Yang, Wei Peng, Yitao Tang, Mia Hofstad, Zhiqun Xie, Heewon Yoon, Liping Chen, Xihui Liu, Sujun Chen, Hong Zhu, Douglas Strand, Han Liang, Ganesh Raj, Housheng Hansen He, Joshua T Mendell, Bo Li, Tao Wang, Ping Mu

Faculty, Staff and Student Publications

Tumor mutational burden and heterogeneity has been suggested to fuel resistance to many targeted therapies. The cytosine deaminase APOBEC proteins have been implicated in the mutational signatures of more than 70% of human cancers. However, the mechanism underlying how cancer cells hijack the APOBEC mediated mutagenesis machinery to promote tumor heterogeneity, and thereby foster therapy resistance remains unclear. We identify SYNCRIP as an endogenous molecular brake which suppresses APOBEC-driven mutagenesis in prostate cancer (PCa). Overactivated APOBEC3B, in SYNCRIP-deficient PCa cells, is a key mutator, representing the molecular source of driver mutations in some frequently mutated genes in PCa, including FOXA1, …

Ramucirumab Plus Erlotinib Versus Placebo Plus Erlotinib In Previously Untreated Egfr-Mutated Metastatic Non-Small-Cell Lung Cancer (Relay): Exploratory Analysis Of Next-Generation Sequencing Results, E B Garon, M Reck, K Nishio, J V Heymach, M Nishio, S Novello, L Paz-Ares, S Popat, S Ponce Aix, H Graham, B D Butts, C Visseren-Grul, K Nakagawa

Faculty, Staff and Student Publications

Background: Ramucirumab plus erlotinib (RAM + ERL) demonstrated superior progression-free survival (PFS) over placebo + ERL (PBO + ERL) in the phase III RELAY study of patients with epidermal growth factor receptor (EGFR)-mutated metastatic non-small-cell lung cancer (EGFR+ mNSCLC; NCT02411448). Next-generation sequencing (NGS) was used to identify clinically relevant alterations in circulating tumor DNA (ctDNA) and explore their impact on treatment outcomes.

Patients and methods: Eligible patients with EGFR+ mNSCLC were randomized 1 : 1 to ERL (150 mg/day) plus RAM (10 mg/kg)/PBO every 2 weeks. Liquid biopsies were to be prospectively collected at baseline, cycle 4 (C4), and …

Poziotinib In Treatment-Naive Nsclc Harboring Her2 Exon 20 Mutations: Zenith20-4, A Multicenter, Multicohort, Open-Label, Phase 2 Trial (Cohort 4), Robin Cornelissen, Arsela Prelaj, Sophie Sun, Christina Baik, Mirjana Wollner, Eric B Haura, Hirva Mamdani, Jonathan W Riess, Federico Cappuzzo, Marina C Garassino, John V Heymach, Mark A Socinski, Szu-Yun Leu, Gajanan Bhat, Francois Lebel, Xiuning Le, Zenith20-4 Investigators

Faculty, Staff and Student Publications

Introduction: ERBB2 or HER2 alterations are found in approximately 2% to 5% of NSCLCs; most are exon 20 insertion mutations. The efficacy and safety of poziotinib, an oral tyrosine kinase inhibitor, were assessed in patients with treatment-naive NSCLC whose tumors harbor HER2 exon 20 insertions.

Methods: ZENITH20 is an open-label, multicohort, multicenter, global, phase 2 trial. ZENITH20-C4 enrolled treatment-naive patients with NSCLC with tumors harboring HER2 exon 20 insertions. Poziotinib was administered 16 mg once daily (QD) or 8 mg twice daily (BID). The primary end point was objective response rate (ORR) by independent central review. Secondary and exploratory end …